#建學生信息表student create table student ( sno varchar(20) not null primary key, sname varchar(20) not null, ssex varchar(20) not null, sbirthday datetime, class varchar(20) ); #建立教師表 create table teacher ( tno varchar(20) not null primary key, tname varchar(20) not null, tsex varchar(20) not null, tbirthday datetime, prof varchar(20), depart varchar(20) not null ); #建立課程表course create table course ( cno varchar(20) not null primary key, cname varchar(20) not null, tno varchar(20) not null, foreign key(tno) references teacher(tno) ); #建立成績表 create table score (
id int auto_increment primary key, sno varchar(20) not null, foreign key(sno) references student(sno), cno varchar(20) not null, foreign key(cno) references course(cno), degree decimal ); #添加學生信息 insert into student values('108','曾華','男','1977-09-01','95033'); insert into student values('105','匡明','男','1975-10-02','95031'); insert into student values('107','王麗','女','1976-01-23','95033'); insert into student values('101','李軍','男','1976-02-20','95033'); insert into student values('109','王芳','女','1975-02-10','95031'); insert into student values('103','陸君','男','1974-06-03','95031'); #添加教師表 insert into teacher values('804','李誠','男','1958-12-02','副教授','計算機系'); insert into teacher values('856','張旭','男','1969-03-12','講師','電子工程系'); insert into teacher values('825','王萍','女','1972-05-05','助教','計算機系'); insert into teacher values('831','劉冰','女','1977-08-14','助教','電子工程系'); #添加課程表 insert into course values('3-105','計算機導論','825'); insert into course values('3-245','操作系統','804'); insert into course values('6-166','數字電路','856'); insert into course values('9-888','高等數學','831'); #添加成績表 insert into score values(1,'103','3-245','86'); insert into score values(2,'105','3-245','75'); insert into score values(3,'109','3-245','68'); insert into score values(4,'103','3-105','92'); insert into score values(5,'105','3-105','88'); insert into score values(6,'109','3-105','76'); insert into score values(7,'103','3-105','64'); insert into score values(8,'105','3-105','91'); insert into score values(9,'109','3-105','78'); insert into score values(10,'103','6-166','85'); insert into score values(11,'105','6-166','79'); insert into score values(12,'109','6-166','81');
1、 查詢Student表中的所有記錄的Sname、Ssex和Class列。
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1
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select
Sname,Ssex,Class
from
student
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2、 查詢教師所有的單位即不重復的Depart列。
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select
distinct
Depart
from
teacher
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3、 查詢Student表的所有記錄。
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select
*
from
student
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4、 查詢Score表中成績在60到80之間的所有記錄。
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select
*
from
Score
where
Degree
between
60
and
80
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5、 查詢Score表中成績為85，86或88的記錄。
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1
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select
*
from
Score
where
Degree
in
(85,86,88)
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6、 查詢Student表中“95031”班或性別為“女”的同學記錄。
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select
*
from
Student
where
class=
'95031'
or
Ssex=
'女'
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7、 以Class降序查詢Student表的所有記錄。
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select
*
from
student
order
by
class
desc
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8、 以Cno升序、Degree降序查詢Score表的所有記錄。
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1
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select
*
from
Score
order
by
cno
asc
,degree
desc
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9、 查詢“95031”班的學生人數。
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1
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select
count
(*)
from
student
where
class=
'95031'
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10、 查詢Score表中的最高分的學生學號和課程號。（子查詢或者排序）
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select
Sno,Cno
from
Score
where
Degree=(
select
max
(Degree)
from
Score)
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1
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select
Sno,Cno
from
Score
order
by
Degree
desc
limit 0,1
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11、 查詢每門課的平均成績。
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1
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select
Cno,
avg
(degree)
from
Score
group
by
Cno
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12、 查詢Score表中至少有5名學生選修的並以3開頭的課程的平均分數。
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select
avg
(Degree)
from
score
where
Cno
like
'3%'
and
Cno
in
(
select
Cno
from
score
group
by
Cno
having
count
(*)>=5) 用
in
不用= 是因為可能會有多個
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簡單寫法：
select
avg
(Degree)
from
score
where
Cno
like
'3%'
and
group
by
Cno
having
count
(*)>=5
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13、 查詢分數大於70，小於90的Sno列。
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1
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select
Sno
from
Score
where
degree>70
and
degree<90
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14、 查詢所有學生的Sname、Cno和Degree列。
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select
Sname, Cno,Degree
from
Score , student
where
Score.Sno=student.Sno
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15、 查詢所有學生的Sno、Cname和Degree列。
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select
Sno,Cname,Degree
from
Score , Course
where
Score.Cno=Course.Cno
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16、 查詢所有學生的Sname、Cname和Degree列。
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select
Sname,Cname,Degree
from
student,course,score
where
student.Sno=score.Sno
and
course.Cno=score.Cno
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join
..
on
寫法：
select
Sname,Cname,Degree
from
student
join
score
on
student.Sno=score.Sno
join
course
on
course.Cno=score.Cno
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17、 查詢“95033”班學生的平均分。
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1
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select
avg
(degree)
as
'class=95033'
from
Score
where
Sno
in
(
select
Sno
from
Student
where
Class=
'95033'
)
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18、 假設使用如下命令建立了一個grade表：
create table grade(low int(3),upp int(3),rank char(1))
insert into grade values(90,100,’A’)
insert into grade values(80,89,’B’)
insert into grade values(70,79,’C’)
insert into grade values(60,69,’D’)
insert into grade values(0,59,’E’)
現查詢所有同學的Sno、Cno和rank列。
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select
Sno,Cno,rank
from
Score,grade
where
degree
between
low
and
upp
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19、查詢選修“3-105”課程的成績高於“109”號同學成績的所有同學的記錄。
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<span style=
"color: #000000; font-size: 15px"
>109同學，選修是3-105課的</span>
|
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1
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select
*
from
score
where
Cno=
'3-105'
and
degree>(
select
max
(degree )
from
Score
where
Sno=
'109'
and
Cno=
'3-105'
)
|
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1
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<span style=
"font-size: 15px"
>109同學，沒有選修3-105課</span>
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1
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select
*
from
score
where
Cno=
'3-105'
and
degree>(
select
max
(degree )
from
Score
where
Sno=
'109'
)
|
and degree<( select max(degree ) from Score where sno in (select Sno from score group by Sno having count(*)>1))
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選了多門課程並且是這個課程下不是最高分的
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select
*
from
score a
where
Sno
in
(
select
Sno
from
score
group
by
Sno
having
count
(*)>1)
and
degree<(
select
max
(degree )
from
Score b
where
b.cno = a.cno)
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21、查詢成績高於學號為“109”、課程號為“3-105”的成績的所有記錄。
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1
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Select
*
from
score
where
degree>(
select
degree
from
Score
where
Sno=
'109'
and
Cno=
'3-105'
)
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22、查詢和學號為108、101的同學同年出生的所有學生的Sno、Sname和Sbirthday列。
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select
sno,sname,sbirthday
from
student
where
year
(sbirthday) = (
select
year
(sbirthday)
from
student
where
sno=
'108'
)
|
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1
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select
sno,sname,sbirthday
from
student
where
year
(sbirthday) = (
select
year
(sbirthday)
from
student
where
sno=
'101'
)
|
23、查詢“張旭“教師任課的學生成績。
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1
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select
Sno,degree
from
score,Course
where
score.Cno=Course.Cno
and
Course.Tno= (
select
Tno
from
Teacher
where
Tname=
'張旭'
)
|
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1
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select
degree
from
score
where
Cno
in
(
select
cno
from
course
where
Tno= (
select
Tno
from
Teacher
where
Tname=
'張旭'
) )
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24、查詢選修某課程的同學人數多於5人的教師姓名。
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1
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select
Tname
from
Teacher, Course
where
Teacher.Tno=Course.Tno
and
Course.Cno =(
select
Cno
from
Score
group
by
Cno
having
count
(*)>5)
|
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1
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select
Tname
from
Teacher
where
tno=(
select
Tno
from
Course
where
cno=(
select
Cno
from
Score
group
by
Cno
having
count
(*)>5 ))
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25、查詢95033班和95031班全體學生的記錄。
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1
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select
*
from
student
where
class
in
(
'95033'
,
'95031'
)
|
26、 查詢存在有85分以上成績的課程Cno.
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1
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select
Cno
from
score
where
degree>85
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27、查詢出“計算機系“教師所教課程的成績表。
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1
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select
*
from
course
where
cno
in
(
select
cno
from
course
where
tno
in
(
select
tno
from
teacher
where
Depart=
'計算機系'
))
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28、查詢“計算 機系”與“電子工程系“不同職稱的教師的Tname和Prof。
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1
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select
Tname,Prof
from
Teacher
where
Depart =
'計算機系'
and
Prof
not
in
(
select
Prof
from
Teacher
where
Depart =
'電子工程系'
)<br>
union
<br>
select
Tname,Prof
from
Teacher
where
Depart =
'電子工程系'
and
Prof
not
in
(
select
Prof
from
Teacher
where
Depart =
'計算機系'
)
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29、查詢選修編號為“3-105“課程且成績至少高於選修編號為“3-245”的同學的Cno、Sno和Degree,並按Degree從高到低次序排序。
any:代表括號中任意一個成績就可以
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1
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select
Cno,Sno,Degree
from
score
where
cno=
'3-105'
and
degree >
any
(
select
degree
from
score
where
cno=
'3-245'
)
order
by
degree
desc
|
30、查詢選修編號為“3-105”且成績高於選修編號為“3-245”課程的同學的Cno、Sno和Degree.
all:代表括號中的所有成績
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1
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select
Cno,Sno,Degree
from
score
where
cno=
'3-105'
and
degree >
all
(
select
degree
from
score
where
cno=
'3-245'
)
order
by
degree
desc
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31、 查詢所有教師和同學的name、sex和birthday.
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1
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select
tname,tsex,tbirthday
from
Teacher
union
select
sname,ssex,sbirthday
from
Student
|
32、查詢所有“女”教師和“女”同學的name、sex和birthday.
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1
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select
Tname,Tsex,Tbirthday
from
Teacher
where
Tsex=
'女'
union
select
Sname,Ssex,Sbirthday
from
Student
where
Ssex=
'女'
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33、 查詢成績比該課程平均成績低的同學的成績表。
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1
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select
*
from
score a
where
degree < (
select
avg
(degree)
from
score b
where
b.cno=a.cno)
|
34、 查詢所有任課教師的Tname和Depart.
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1
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select
Tname,Depart
from
Teacher
where
tno
in
(
select
tno
from
course )
|
35 、 查詢所有未講課的教師的Tname和Depart.
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1
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select
Tname,Depart
from
Teacher
where
Tno
not
in
(
select
Tno
from
Course
where
cno
in
(
select
cno
from
score ))
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36、查詢至少有2名男生的班號。
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1
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select
class
from
student
where
ssex=
'男'
group
by
class
having
count
(*)>1
|
37、查詢Student表中不姓“王”的同學記錄。
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1
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select
*
from
Student
where
Sname
not
like
'王%%'
|
38、查詢Student表中每個學生的姓名和年齡。
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1
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select
Sname,
year
(now())-
year
(sbirthday)
from
Student
|
39、查詢Student表中最大和最小的Sbirthday日期值。
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1
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select
Max
(Sbirthday ),
Min
(Sbirthday )
from
Student
|
40、以班號和年齡從大到小的順序查詢Student表中的全部記錄。
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1
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select
*
from
Student
order
by
class
desc
, Sbirthday
|
41、查詢“男”教師及其所上的課程。
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select
Tname,Cname
from
course,teacher
where
course.tno= teacher.tno
and
teacher.Tsex=
'男'
|
42、查詢最高分同學的Sno、Cno和Degree列。
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1
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select
Sno,Cno,Degree
from
score
where
degree=(
select
max
(degree)
from
score)
|
排序寫法：
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select
Sno,Cno,Degree
from
score
order
by
degree
desc
limit 0,1
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43、查詢和“李軍”同性別的所有同學的Sname.
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1
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select
Sname
from
Student
where
Ssex = (
select
Ssex
from
Student
where
Sname=
'李軍'
)
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44、查詢和“李軍”同性別並同班的同學Sname.
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1
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select
Sname
from
Student
where
Ssex = (
select
Ssex
from
Student
where
Sname=
'李軍'
)
and
class=(
select
class
from
student
where
Sname=
'李軍'
)
|
45、查詢所有選修“計算機導論”課程的“男”同學的成績表。
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1
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select
Sno,Cno,degree
from
score
where
Cno=(
select
Cno
from
course
where
Cname=
'計算機導論'
)
and
Sno
in
(
select
Sno
from
student
where
Ssex=
'男'
)
|